Method of forming hermetic closures



J. G. HODGSON.

METHOD OF FQRMING HERMETIC CLOSURES.

I APPLICATION FILED APR. 3. I916- 1,332,838. A Patented Mar. 2,1920.

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ILLINOIS, ASSIGNOB '10 AMERICAN CARI COMPANY,

.e conroaa'rron or NEW JERSEY.

I METHOD OF FORMING HERMETIG CLOSURES.

Original application filed September 14, 1914, Serial No. 861,584.Divided 1916. Serial No. 88,503.

I particularly to the manufacture and use of the cooking process inorder to sheet metal containers in the canning industry.

In canning vegetables and other food stuffs of various kinds it is acustom to cook the materials after they have been placed in the cans inwhich they are to be sold to the trade. In order that the materialsbeing canned may be properly pre served, the cans are permanentl andhermetically closed during or immediately after prevent the entrance ofgerms and ferments.

It has frequently been the custom pr1or to my invention to permanentlyclose the cans either by seaming or by plugging vents immediately uponthe termlnation of the cooking step and to then lacquer the seam orclosed vents while the can is still extremely hot and before anycontraction of the material takes place. This process has been foundefiicient when used in canning food stuffs wherein the period of heatingor cooking need not be accurately determined and observed. In thecanning of peasand other vegetables, however, where the quality of thecooked product depends in great degree upon the sudden cooling of thecan and consequent termination of the cooking step, the method has notbeen found so satisfactory, in cooking peas and the like it is thecustom to immerse the cans in cool or cold water as soon as they arereceived from the cooking chamber, insufficient time bemg given to applythe coating of lacquer.

It is a purpose of this inventlon to provide a method for preparing thecan, and hermetically sealing the can during the cooking or processingoperation, so that it will not be necessary to wait until after the canhas come from the cooking chamber.

It is a principal object of the present invention to rovide an improvedhermetic sealing met 0d, so that the seal automati- Specification ofLetters Patent.

Patented Mar. 2, 1920.

and this application filed April 8,

' ca'lly applies itself during the processing of a contamer or can.

A further object of the invention is to so cause the formin of ahermetic seal between the can bo y and closure or end that. nomampulatlon by the packer or canner is requlred other than seaming thecontainer in the ordinary manner.

Other objects and advantages of the invention Will be apparent as it isbetter understood from the following description when considered inconnection with the accompanying drawing illustrating a preferred mannerof carrying it into effect.

Referring to the drawing Figure :1 shows a can or container for useaccording to my invention the same being hermetically sealed.

Fig. 2 is a side elevation of the can Body. Fig. 3 is a transversesection of an end or closure for the same; and

Fig. 4 is a partial transverse sectional view showing the closure andend of the body seamedtogether.

For the purpose of illustrating my inven- 'tion I haveillustrated it inconnection with a can of an ordinary and well known type in which theends and body are joined by a double seam.

The can body 5 in the present instance is provided with outwardlyextending flan ed end edges 6 of the ordinary type adaptetf to be turnedover, as seen in Fig. 4, in forming the double seam. On the under sideof these flanges and extending longitudinally of the body is painted orotherwise provided a film or coating 7 of some gummy material adapted toexpand and soften under heat. The extent of this film or coating ispreferably such that when the seam is formed the coating will terminateat or about the seam, as seen at 8 in Fig.4. The cover or end 9 in thepresent instance is provided with an outwardly extending flan e 10turned down slightly at its edges 11 1n the 13 may be omitted. \Films 7and 13, after being placed on the can, are permitted to dry and the formlittle more than a coat of lacquer o the ordinar thickness in the rdried condition. When t e can is seamed it will be noted that thecoating 7 on the can body is'brought opposite the adjacent surfaces ofthe cover and the coating 13, if used, is brought opposite the adJacentsurface of the can body. These coatin s are providedand aresubstantially dried fore the ends are sec red to the body and they maybe provid if desired, on the blanks before the ends or body are formed.When the can has en seamed and is hot from processing 0 in processing,the lacquer or sealing material softens and swells and forms a filmadhering to the adjacent surfaces of the body and cover to form ahermetic seal.

The manner of forming the double seam is or may be such that horizontalpressure "s thereby applied to the seam so as to tightly compress boththe paper liner and the cement, the said sealing elements be ngordinarily located in the seam one outside of the other with the bodyflange 6 interposed between them.

In practice it is customary to secure one end to the can body at the canfactory and to supply the other end free of the can to subsequently bepositioned and attached by the acker or canner.

W ere cans are provided according tov both, it only being necessary forthe canner or packer to fill the can with its contents and process'it inthe usual manner, the resulting product being hermetically sealedwithout the necessity of subsequently lacquering the can in the mannerearlier described. Such a can filled and sealed in proper manner willhide completely the lacquer film and. an article more pleasing inappearance is thereby produced than is possible where the lacquer ispainted over'the seamed ed e after vprocessing.

The ac ing 12 is or may e a aper ring liner. he film or coatin 7 may eapplied with some accuracy so t at after the seam has been formed saidfilm will be entirely embraced within the seam and will not appear atall on the surface of the body outside of the seam. During theprocessing operation the two films 7 and 13 unite, so that a single filmis in effect formed the inner side of which is hermetically united withthe body of the container and the outer side of which ishermeticallyunited with the inturned edge of the cover, and the middle ortion ofwhich consists of the united and in efiect integral film bodies.

The films 7 and 13 or either of them singly I have termed herein as alacquer. It might be stated, however, that I have only used this termrelatively, it may bea lacquer of low melting point, or it may be afused .cement. It is preferably applied to the flange surfaces in a liuid state and dried by heat or otherwise, an is then fused by theprocessing heat and caused to'hermetically seal the joint in which it isincorporated.

It is also to be noted that I provide two distinct and separablyefiicientsealing means. The first comprising a sealing liner interposedbetween the under surface of the can cover flange, and the upper-surfaceof the can body flange; and the second a sealing medium interposedbetween the wall of the can body andthe outer surface of the can coverflange; this latter sealing medium providing a hermetic joint in aportion of the double seam that has not been sealed hermeticallyheretofore except as I have mentioned, by applying a sealing compoundafter the seam was finally completed.

The operation of double seaming and finally closing a double seam,containing a packing, into a hermetic joint, requires so much pressurethat the metallic surfaces in the seam are pressed so tightly togetherthat it is next to impossible to apply a sealing compound to theinterstices of a tightly rolled seam and have it penetrate between thesurfaces it is desired to seal, the result being that the seal is madeon the outside and the sealing medium is more or less exposed toabrasion or mutilation from the ordinary handling of canned goods.

The fusible seal I apply, however, is incorporated in the seam duringits formation,

and when the material is fused by the processing heat, it instantlyunites with the surfaces between which it is lodged and produces ahermetic joint separate and distinct from the regular hermetic jointformed by means of the sealing liner interposed in the seam in theordinary manner.

A suitable material to act as a lacquer could be made of water whiteresin stiffened with five to ten per cent. of sandarac to which would beadded carnauba wax and about five er cent. of castor oil.

A suitab e fusible cement or gum might be made of chicle mixed with somewaxy material similar to a high melting parafiin or esmonta wax andfilled with magnesium oxid or magnesium carbonate or mixtures of thetwo, or a mixture of gelatin and glycerin in suitable proportions andproperly compounded will form a rubbery com lposition that will fuseunder processing eat;

I This application is a division of my application, Serial No. 861,53'i,filed Septemher 14th, 1914.

, end closure,

- It is thou ht that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various chan es may be made in the procedure, withouteparting from the spirit and scope of the invention or sacrificing anyof its material adantages;

What is claimed is:

1. A method of forming a hermetic roll seam joint between a containerbody and an consisting in forming an outstanding flange on a containerbody, coating the said flange with a fusible cement, a plying a sealingliner to the outstanding ange of a can cover, interfolding the saidflanges into a rolled seam and thereby attaching the can cover to thecan body, whereby the sealing liner on the can cover forms a hermeticjoint between adjacent surfaces of the seam, and applying heat to theseam for fusing the cement, whereby the fusible cement forms a hermeticjoint between adjacent surfaces of the seam, the two joints beingindependent in their sealin capacities.

2. A method of forming a hermetic closure between a container body and acover, consistin in coating an end of the container body wit a fusiblecement, applying a sealing gasket or material to the seam portion ofacan cover, formin an interfolded joint or seam uniting the body andcover, and applying heat to the seam for fusin the cement and applyingpressure, where y the said fusible cement forms a hermetic seal in oneportion of the said joint and the said sealing gasket or material formsa hermetic seal in another portion of the said joint.

3. A method of forming a hermetic clo sure between 'a sheet metal bodyelement having an outstanding flange, and a sheet metal end element,which consists in applying a sealing liner to one of said elements,coating one of said elements with a fusible cement, bendingand'interfolding the parts to which said hner and cement are appliedcontacting and thereby forming a double seam in which said liner 1s heldbetween the outer face of the flange of the body and the under face ofthe end, and said cement is held between the vertical exterior face ofthe body and the contacting face of the said end, and applying by saldformation of the seam horizontal pressure both to said liner and to saidcement.

4. A method of forming a hermetic closure between a sheet metal bodyelement having an outstanding flange, and a sheet metal end element,whlch consists in applying a sealing liner to one of said elements,coating one of said elements with a fusible cement, bending andinterfolding the parts to which said liner and cement are applied andthereby forming a double scam in which said liner is held between theouter face of the flange of the body and the under face of the end, andsaid cement is held between the vertical exterior face of the body andthe face of the said end, and applying by said formation of the seamhorizontal pressure both to said liner and to said cement, and applyingheat to the seam for fusing the cement.

5. A method of forming a hermetic closure between a can body and a canend, which consists in applying a lacquer to the metal parts which areto be comprised in the outer portion of the seam, drying and hardeningsaid lacquer, applying a gasket so as to fill the inner part of theseam, interfolding the flanges of the can body and can end to form adouble seam, and at the same time a plying pressure to the said gasketand to tl' fe said lacquered parts of the seam, and applying heat tocause the lacquer to fill that portion of the seam in which it isinclosed.

In testimony whereof I afiixmy signature hereto.

' JOHN G. HODGSON. Witnesses:

J. C. CARPENTER, Es'rnmz ABRAMS.

